1. Field of the Invention
The present invention relates to a resin composite material comprising graphite particles.
2. Related Background Art
Conventionally, addition of various fillers to a resin has been studied for imparting characteristics of the filler to the resin. For example, graphite particles are a filler excellent in heat resistance, chemical resistance, mechanical strength, thermal conductivity, electrical conductivity, and the like, and it is known that characteristics of graphite particles can be imparted to a resin by adding the graphite particles to the resin. However, graphite particles are likely to aggregate, and moreover have low affinity for resins. Hence, graphite particles are dispersed in a resin in an aggregated state. Therefore, it is difficult to cause characteristics of graphite particles to be expressed sufficiently. Moreover, there is a problem that when a large amount of graphite particles are added for sufficient expression of characteristics of graphite particles, a resultant molded article becomes hard and brittle.
In this respect, the following methods are proposed as methods for highly dispersing graphite particles in a resin: a method in which a surface of a carbon filler such as graphite is modified with a carboxylic acid ester to change the properties of the surface, and then the modified carbon filler is added to a polymer (for example, International Application Japanese-Phase Publication No. 2002-508422); and a method in which a graphite oxide having organic onium ions intercalated therein is melt kneaded with a thermoplastic resin (Japanese Unexamined Patent Application Publication No. 2006-233017). However, when graphite particles are subjected to a surface modification treatment as described above, the characteristics (in particular, electrical conductivity) of the graphite particles tend to be impaired. For this reason, although the graphite particles are highly dispersed in the resin, the characteristics of the graphite particles are insufficiently imparted to the resin.
Moreover, Japanese Unexamined Patent Application Publication No. 2009-144000 proposes a resin composite material having a reduced amount of graphite particles. The resin composite material comprises a carbon fiber and a graphite powder at a specific ratio. It is also disclosed that this resin composite material is excellent in heat dissipation capability, electrical conductivity, impact resistance, and the like. However, such a resin composite material still does not have sufficiently high thermal conductivity or elastic modulus.